Attachment 17531 Details for Bug 15186 – EA-filtering VFS module PoC

[patch] EA-filtering VFS module PoC

samba-4.15.5-vfs_filter_lustre_private_xattr.patch (text/plain), 5.29 KB, created by Michael Weiser on 2022-09-26 07:48:23 UTC

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Creator: Michael Weiser

Created: 2022-09-26 07:48:23 UTC

Size: 5.29 KB

patch

obsolete

>diff -ur samba-4.15.5.ori/source3/modules/wscript_build samba-4.15.5/source3/modules/wscript_build
>--- samba-4.15.5.ori/source3/modules/wscript_build	2021-08-09 15:38:36.435381200 +0200
>+++ samba-4.15.5/source3/modules/wscript_build	2022-09-15 10:05:38.690716949 +0200
>@@ -641,3 +641,10 @@
>                  init_function='',
>                  internal_module=bld.SAMBA3_IS_STATIC_MODULE('vfs_widelinks'),
>                  enabled=bld.SAMBA3_IS_ENABLED_MODULE('vfs_widelinks'))
>+
>+bld.SAMBA3_MODULE('vfs_filter_lustre_private_xattr',
>+                 subsystem='vfs',
>+                 source='vfs_filter_lustre_private_xattr.c',
>+                 init_function='',
>+                 internal_module=bld.SAMBA3_IS_STATIC_MODULE('vfs_filter_lustre_private_xattr'),
>+                 enabled=bld.SAMBA3_IS_ENABLED_MODULE('vfs_filter_lustre_private_xattr'))
>diff -ur samba-4.15.5.ori/source3/wscript samba-4.15.5/source3/wscript
>--- samba-4.15.5.ori/source3/wscript	2021-10-27 14:53:55.900512200 +0200
>+++ samba-4.15.5/source3/wscript	2022-09-15 10:12:05.717420975 +0200
>@@ -1886,7 +1886,8 @@
>                                       'vfs_preopen', 'vfs_catia',
>                                       'vfs_media_harmony', 'vfs_unityed_media', 'vfs_fruit', 'vfs_shell_snap',
>                                       'vfs_commit', 'vfs_worm', 'vfs_crossrename', 'vfs_linux_xfs_sgid',
>-                                      'vfs_time_audit', 'vfs_offline', 'vfs_virusfilter', 'vfs_widelinks'])
>+                                      'vfs_time_audit', 'vfs_offline', 'vfs_virusfilter', 'vfs_widelinks',
>+                                      'vfs_filter_lustre_private_xattr'])
>     if host_os.rfind('linux') > -1:
>         default_shared_modules.extend(['vfs_snapper'])
> 
>--- /dev/null	2022-08-08 11:10:15.373334812 +0200
>+++ samba-4.15.5/source3/modules/vfs_filter_lustre_private_xattr.c	2022-09-15 12:52:27.908346500 +0200
>@@ -0,0 +1,120 @@
>+/*
>+ * VFS module filtering lustre-internal xattrs such as lustre.lov.
>+ *
>+ * Copyright (C) Tim Potter, 1999-2000
>+ * Copyright (C) Alexander Bokovoy, 2002
>+ * Copyright (C) Stefan (metze) Metzmacher, 2003
>+ * Copyright (C) Jeremy Allison 2009
>+ *
>+ * This program is free software; you can redistribute it and/or modify
>+ * it under the terms of the GNU General Public License as published by
>+ * the Free Software Foundation; either version 3 of the License, or
>+ * (at your option) any later version.
>+ *
>+ * This program is distributed in the hope that it will be useful,
>+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
>+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>+ * GNU General Public License for more details.
>+ *
>+ * You should have received a copy of the GNU General Public License
>+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
>+ */
>+
>+#include "includes.h"
>+
>+#undef DBGC_CLASS
>+#define DBGC_CLASS DBGC_VFS
>+
>+#define MODULE_NAME "filter_lustre_private_xattr_fgetxattr"
>+
>+static ssize_t vfs_filter_lustre_private_xattr_fgetxattr(
>+		vfs_handle_struct *handle, struct files_struct *fsp,
>+		const char *name, void *value, size_t size)
>+{
>+	if (strcmp(name, "lustre.lov") == 0) {
>+		DEBUG(5, ("vfs_filter_lustre_private_xattr_fgetxattr: "
>+			"ignoring ea lustre.lov\n"));
>+		errno = ENOTSUP;
>+		return -1;
>+	}
>+
>+	return SMB_VFS_NEXT_FGETXATTR(handle, fsp, name, value, size);
>+}
>+
>+static ssize_t vfs_filter_lustre_private_xattr_flistxattr(
>+		vfs_handle_struct *handle, struct files_struct *fsp,
>+		char *list, size_t size)
>+{
>+	ssize_t rsize = SMB_VFS_NEXT_FLISTXATTR(handle, fsp, list, size);
>+	char *p = list, *op = list;
>+
>+	if (rsize < 0) {
>+		return rsize;
>+	}
>+
>+	while (p < list + rsize) {
>+		/* walk to next nul terminator */
>+		while (*p != '\0' && p < list + rsize) {
>+			p++;
>+		}
>+
>+		/* not nul-terminated? buffer overflow? - we didn't do it */
>+		if (p >= list + rsize) {
>+			break;
>+		}
>+
>+		/* move past nul */
>+		p++;
>+
>+		DEBUG(10, ("vfs_filter_lustre_private_xattr_flistxattr: "
>+			"looking at ea %s\n", op));
>+
>+		/* can there be multiple occurences? */
>+		while (strcmp(op, "lustre.lov") == 0) {
>+			DEBUG(5, ("vfs_filter_lustre_private_xattr_flistxattr: "
>+				"found ea %s to ignore\n", op));
>+
>+			/* 012 345 678
>+			 * aa\0bb\0cc\0
>+			 * ^op ^p */
>+			ssize_t ignorelen = p - op;
>+			if (p < list + rsize) {
>+				/* move the rest forward and nul out the
>+				 * overhang */
>+				ssize_t rest = rsize - (p - list);
>+				memmove(op, p, rest);
>+				memset(op + rest, '\0', ignorelen);
>+
>+				DEBUG(10, ("vfs_filter_lustre_private_xattr_flistxattr: "
>+					"moved buffer forward %p:%ld:%p:%p:%ld:%ld\n",
>+					list, rsize, op, p, ignorelen, rest));
>+			} else {
>+				/* just null the end */
>+				memset(op, '\0', ignorelen);
>+
>+				DEBUG(10, ("vfs_filter_lustre_private_xattr_flistxattr: "
>+					"nulled buffer end %p:%ld:%p:%p:%ld\n",
>+					list, rsize, op, p, ignorelen));
>+			}
>+
>+			rsize -= ignorelen;
>+		}
>+
>+		op = p;
>+	}
>+
>+	return rsize;
>+}
>+
>+static struct vfs_fn_pointers vfs_filter_lustre_private_xattr_fns = {
>+	.fgetxattr_fn = vfs_filter_lustre_private_xattr_fgetxattr,
>+	.flistxattr_fn = vfs_filter_lustre_private_xattr_flistxattr,
>+};
>+
>+static_decl_vfs;
>+NTSTATUS vfs_filter_lustre_private_xattr_init(TALLOC_CTX *ctx)
>+{
>+	return smb_register_vfs(SMB_VFS_INTERFACE_VERSION,
>+			"filter_lustre_private_xattr",
>+			&vfs_filter_lustre_private_xattr_fns);
>+}

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Attachments on bug 15186: 17531 | 17532 | 17533 | 17606